You misunderstand, I meant after the pump shot has phased out, it only last a second or 2.
It's after this that I'm experiencing the lean situation.
It's like this:
cruising, press throttle to accelerate and hold throttle at that position, pump shot, lean condition.

383B, 9.8:1, Lunati 60302(220/226@0.050 262/268Dur, 0.475"/0.494", Stealth heads, Performer manifold, QF SS-750-AN carb, 3.31Diff, A833 4-speed manual.